The purpose of this project is to characterize the female Yucatan Miniature Pig as a model for maturity-onset diabetes mellitus. Obesity, resulting from ad libitum consumption of either a high starch or high sucrose diet, combined with pregnancy and lactation are employed as diabetogenic stresses superimposed upon genetically impaired glucose tolerance in order to exacerbate the intolerance and produce overt diabetes. Periodic testing of fasting blood glucose, insulin and lipid concentrations, intravenous glucose tolerance, insulin tolerance and in vivo insulin impedance are used to assess the development of the prediabetic and diabetic states.